1. Field of The Invention
The invention relates to card edge electrical connectors, particularly to a SIMM socket having miniature dimensions and lying on a mother board for use within a laptop computer.
2. The Prior Art
SIMM (Single In-Line Memory Module) is popularly used in the personal computer, so the SIMM socket connector is also commonly adopted, to a greater amount, to be an interface between the mother board and such SIMM in the computer industry. As well known, the typical early SIMM socket connector can be referred to U.S. Pat. Nos. 4,832,617 and 4,850,892 showing connectors having integral plastic latches thereof for retaining an inserted daughter board. Later, a separate metal latch substitutes such integral plastic latch for easy and long life-time operation, for example, U.S. Pat. Nos. 4,986,765, 4,995,825, 5,004,429, 5,094,624, 5,100,337, 5,112,242, 5,123,857, 5,145,395, 5,154,627, 5,161,995, 5,174,778, 5,174,780, 5,234,354, 5,244,403, 5,273,451 and 5,286,217. As experienced and shown in aforementioned U.S. Pat. Nos. 4,986,765, 4,995,825, 5,100,337, 5,112,242 and 5,174,778, a U-shaped metal latch is preferably desired due to its inherent good structural resilience which allows easy deflection and reliable recovery.
One disadvantage may be found in that design that strict manufacturing tolerance and precision of the dimensions of the separate metal latch and the corresponding portions of the housing are generally required, which increase production complexity. The reason for this strict request results from a portion of such U-shaped body of the latch also being retention means for retaining the latch within a corresponding pocket, thus causing the significance of the dimensions of the U-shaped body of the latch which intends to not only reliably and effectively retain the latch within pocket of the housing, but also provide the latch itself with outstanding resilience wherein such resilience has a superior elasticity coefficient allowing for not only easy operative deflection but also complete recovery to effectively holding the daughter board within the socket connector.
Most other designs as shown in the aforementioned U.S. Pat. Nos. use a generally simple straight beam to replace such U-shaped body of the latch for simplifying the manufacturing procedure. Although the simple straight beam type latch can be easily fabricated and attachably assembled to the housing, the resilience thereof is inferior to that of the U-shaped body latch. Using a soft material of such latch may allow for easy operative deflection of the latch, but also tend to fail to completely recover the latch after its deflection. Thus, this permanent deformation of the latch precludes the daughter board from being effectively retained within the socket connector. In contrast, using a strong material of the latch may guarantee no permanent deformation of the latch to efficiently retaining the daughter board in the socket connector, but the stiffness of the latch precludes easy operative deflection thereof.
Therefore, an object of the present invention is to provide latch means having the advantage of the good resilience of the U-shaped body thereof, but without the aforementioned disadvantage of manufacturing problems of the U-shaped body as shown in the above-described patents.
It is noted that different from a conventional SIMM socket connector mountably standing on the mother board, a Mini-SIMM socket connector used in a laptop computer lies on the mother board for decreasing the height of the computer set wherein the upper row contacts and the lower row contacts are arranged staggered along the slot of the connector housing.
Another object of the invention is to provide upper row and lower row contacts in the socket connector, each of which has an extended longer curved configuration to provide a good resilience thereof for low insertion force of the inserted daughter board. Also, the elasticity coefficient of the upper row contact and that of the lower row contact are generally equal to each other so that the inserted daughter board in the socket connector can properly receive the balanced forces on its two opposite surfaces.
Yet an object of the invention is to provide a retaining bracket which is designed to be mounted to the mother board for retaining the socket connector on such mother board and is individually separated from the latch so that the force acting on the latch will not be directly transferred to the retaining bracket to influence the retention of the retaining bracket with the mother board.